The invention relates to digital tape drive storage devices, and in particular, to a retracting door assembly for use in a single reel tape cartridge to reduce the area required within the tape drive for opening the door.
It is a problem in the field of single reel tape cartridges to protect the magnetic tape when the tape cartridge is not in use while providing a method for accessing the magnetic tape when the tape cartridge is inserted into the tape drive without requiring excessive area within the tape drive for the door to open. Digital data is stored on magnetic tape utilizing a variety of designs, but in all cases, magnetic tape is wound between a pair of tape reels as data is transferred to or from the magnetic tape. In the art of data storage, the physical space required to store data is an important concern. To conserve space, tape drives often use a single reel cartridge design. The single reel design utilizes a supply reel located within the tape cartridge and a take up reel located within the tape drive. A length of magnetic tape for storing digital data is wound on the supply reel. After the tape cartridge is inserted into the tape drive, the magnetic tape is connected to the takeup reel and wound along a tape path internal to the tape drive.
One example for connecting the magnetic tape located within the tape cartridge to the takeup reel located within the tape drive utilizes a flexible leader tab having a closed loop at the end. The leader tab is attached to the end of the length magnetic tape wound on the supply reel within the tape cartridge. As the tape cartridge is inserted into the tape drive, the tape cartridge door automatically opens and the leader tab obtrudes from the tape cartridge. A leader load mechanism located within the tape drive catches the leader tab closed loop and pulls the leader tab and attached magnetic tape toward the takeup reel along the tape path. The leader load mechanism attaches the leader tab to the takeup reel and the tape drive is ready for operation.
In its normal position, the flexible leader tab obtrudes from the tape cartridge. The leader tab is retracted into the tape cartridge when the door is closed. Thus, the door assembly performs the functions of retracting the leader tab following usage and protecting the leader tab and attached magnetic tape media while the tape cartridge is not in use. The typical solution to the problem has been a door assembly that automatically opens as the tape cartridge is inserted into the tape drive.
Horizontally Pivoting Door
One known door assembly employs a door that pivots horizontally and includes a catch that corresponds to a stop in the tape drive. As the tape cartridge is inserted into the tape drive, the catch makes contact with the indentation in the tape drive causing the door to pivot to the open position. Once open, the door remains within the tape drive during operation. As the pivoting door opens, it arcs through approximately a quarter circular profile. The door assembly just described requires internal tape drive space for the door to horizontally pivot between the open and closed position and area for the opened door during operation.
Vertically Pivoting Door
Another known door assembly incorporates a vertically pivoting door. This design requires additional space within the tape cartridge for the door in its open position. The height of the tape cartridge is dictated by the space required for the magnetic tape and for the opened door. Likewise, the height of the tape drive is influenced by the height of the tape cartridge and the drive mechanism located beneath the inserted tape cartridge.
The tape cartridge door assemblies just described influence the size of the tape drive. The horizontally pivoting door influences the tape drives length while the vertically pivoting door influences the tape drive height.
Sliding Door
Yet another door assembly includes a sliding door, reducing the area required for both opening and stowing the door during use. This design is neither practical for all types of tape cartridge nor compatible with all tape drives. Single reel tape cartridges include a flexible leader tab connected to the end of the tape media. The leader tab must be accessible to the leader load mechanism for operation. Existing tape drives for single reel tape cartridges having a sliding door open the door by sliding the door to the right. The flexible leader tab obtrudes toward the right side of the tape cartridge. The leader load mechanism catches the leader tab, then pulls the leader tab and attached magnetic tape left toward the takeup reel. For compatibility with existing tape drives, the sliding door assembly would have to slide right to open and left to close, catching the leader tab when closing. For the reason just discussed, the sliding door assembly is not compatible with existing single reel tape drives.
For these reasons, a need exists for a retracting door assembly that does not require excessive area within the tape drive to open the door and for the door during operation.
The present retracting door assembly overcomes the problems outlined above and advances the art by providing a retracting door assembly that requires less internal tape drive area for the door to pivot open, less area required for the opened door during operation and is compatible with existing tape drives that utilize single reel tape cartridges with a horizontally pivoting door assembly.
For compatibility with existing single reel tape drives, a retracting door assembly that pivots at least partially internal to the tape cartridge reduces the area required inside the tape drive for pivoting the door between the open and closed positions. Similarly, retaining the door internal to the tape cartridge during operation reduces tape drive length.
An apparatus for drawing the retracting door into the tape cartridge is an engaging apparatus that is pushed into the tape cartridge as the tape cartridge is inserted into the tape drive. A hinge or similar pivoting apparatus attaching the retracting door to the engaging apparatus allows the retracting door to also be drawn into the tape cartridge. The hinge and a portion of the retracting door are drawn into the cartridge as the retracting door pivots to the open position, thereby reducing the arc of motion as the retracting door opens within the tape drive.
The retracting door assembly just described includes tracks, such as a cam, along the internal top and bottom surface of the tape cartridge for the engaging apparatus, a hinge and a retracting door. Addition of a guide adjacent to the tracks provides a method for controlling the arc of motion the retracting door travels internal to the tape drive.
Varying the distance between the guide and the tracks changes the arc of motion the retracting door travels as it opens. As the distance between the guide and the track increases, the hinge is drawn further into the tape cartridge as the door pivots open. Drawing the hinge further into the tape cartridge reduces the internal tape drive area required to open the retracting door. Likewise, drawing the retracting door internal to the tape cartridge reduces the area required within the tape drive for the opened retracting door during operation.
The combination of an engaging apparatus pivotally attached to the retracting door and tracks for guiding the retracting door assembly into the tape cartridge as the tape cartridge is inserted into the tape drive reduces the internal tape drive area required for operation.